module HA (
	   output Cout, Sum,
	   input  A, B );

   wire 	  Cbar, p;
   
   and a1 (Cout, A, B);
   not i1 (Cbar, Cout);
   or o1 (p, A, B);
   and a2 (Sum, Cbar, p);
endmodule // ha
